THE NUTRITIVE VALUE OF FOOD 1063 



The usual stimulant taken by healthy persons is coffee or tea. In 

 addition to ethereal oil, tannic acid and other substances, these articles 

 contain the alkaloid caffeine {Runge, 1820) or theine. Coffee differs 

 from tea in being rich in aromatic material (caffeal). Tea contains 

 a bitter substance, tannin, and hence, it should not be allowed to draw 

 for longer than a few minutes, otherwise too much tannin will enter 

 the solution and produce injurious effects. Similar stimulating drinks 

 are the mate of Paraguay, the guarana of Brazil, the bush-tea of 

 South Africa, and the cola of Central Africa. Not being in possession 

 of caffeine plants, the inhabitants of Mexico derive their stimulating 

 beverage from the fermented seeds of the chocolate plant which contain 

 theobromine. 



Among the alcoholic stimulants might be mentioned the malt 

 liquors, red and white wines, fortified wines, distilled liquors, or spirits, 

 and elixirs. Having a great affinity for water and being a coagulant 

 of protein, alcohol tends to destroy the cells. It should, therefore, be 

 regarded essentially as a protoplasmic poison. Regarding its action 

 as a stimulant and its value as a food, the reader must be referred to 

 the more specialized literature upon this subject, because it is alto- 

 gether too contradictory and extensive to be included in a book of 

 this kind.^ In general, however, it may be said that alcohol does not 

 build up the tissues, although it may serve to spare and to replace fats 

 and carbohydrates for a time and also to protect the proteins. For 

 this reason, it may be considered as an adjunct article of diet but not 

 as a true food. Obviously, its properties of yielding energy are com- 

 pletely overshadowed by its pharmacologic actions as a depressant and 

 irritant. 



1 Welch, "The Pathological Effects of Alcohol;" Abel, "The Pharmac. Action 

 of Alcohol," and Atwater, "The Nutritive Value of Alcohol," in Physiol. Aspects 

 of the Liquor Problem, 1903. 



